Dual Enrollment Earth Science Practice Test

Ultraviolet radiation from the Sun can harm living organisms, so the ozone layer acts as a shield by absorbing most of this UV light before it reaches Earth’s surface. The ozone molecule—three oxygen atoms—occurs primarily in the stratosphere, about 10 to 50 kilometers up, where it absorbs UV and heats the surrounding air. This description fits best because it highlights the key protective role of ozone and its main location, unlike ideas about infrared absorption, reflecting visible light, or being in other layers.